Federal forecasters say it is likely that Lake Mead will receive a larger than usual release of water from Lake Powell in the coming year, as conditions in the two reservoirs approach a trigger point for so-called "equalization."

The extra water for Lake Mead -- 9 million acre-feet instead of the standard 8.23 million acre-feet -- could raise the level of the reservoir by 7 feet or more and delay an unprecedented shortage declaration that would require Nevada and Arizona to cut their river use.

The complicated framework that now decides the coordinated rise and fall of the nation's two largest man-made reservoirs was implemented in late 2007. The rules are designed to protect minimum water levels in lakes Mead and Powell through the year 2026.